Polyps are abnormal growths that typically extend from an inner wall of a hollow organ and may be precursors to more serious ailments such as cancer. Polyps may develop in different parts of a patient's body, for example the gastro intestinal (GI) tract, the uterus, the heart, etc. However, polyps which develop in the intestine, especially in the colon and the rectum, are serious as they are often a precursor for colorectal cancer. Thus, treatment of these polyps before they develop into malignancies is extremely important.
Several procedures available for the removal of polyps generally are applicable to colorectal polyps in particular. Snares are commonly used to grip and remove polyps. In some instances, the polyp is not immediately removed. Rather, the snare is tightened around the polyp and left in place to act as a ligation band, choking the supply of blood to the polyp so that it withers and dies over time.
Various types of snares are commonly used to remove polyps, for example from the intestine wall. These snares all require a mechanism to tighten a loop of the snare around the polyp so that it can be gripped and removed from the underlying tissue layers. Generally, the tightening is done mechanically, by providing a linkage between the loop and a control handle, so that the surgeon can manually tighten the loop. Levers, pulleys, cables or other devices may be used to facilitate the tightening of the loop around the polyp. However, the linkages connecting these loops to the controls and associated elements is often bulky, making the snare device too large to be inserted endoscopically and/or to be manipulated as necessary.
Polyps may also be removed through hot biopsy in which a forceps is used to grip the polyp between jaws which are heated to ablate the base of the polyp so it can be retrieved and evaluated. Destructive techniques such as argon beam coagulation are also used to treat polyps. In these procedures, energy (e.g., laser energy) is directed to the polyp to necrose the tissue.